Main Menu / Switchboard Problem

I have inherited a database where the main menu was a standard Access switchboard.

Having built a database from scratch in Access and used a form as my main menu because you can get many more options and buttons on it, I decided to edit the inherited database and employ the same method.

However, after initially working fine, problems started to occur with the inherited database and my new form style main menu stopped working, so I reverted to the switchboard again.

I have today decided to re-introduce my main menu and thought the problems lie with the original switchboard, so deleted it.

Now, when you open the database, the main menu refuses to work at all, triggering 'an error' message when in 'user' mode. Opening the form in edit mode seems ok, but as I am setting it up for others to use besides me, it needs to be seemless.

Any ideas on what I have done wrong and how I can correct it.

Inicidentally, the db I built from scratch, which never had switchboard involved is working fine on a daily basis.